Stereoscopic eyepiece for microscopes



Oct. 16 1923.

O. HEIMSTADT sTEREoscoPIc EYEPIEGE FOR MIcRoscoPEs Filed Feb. 23 1921 Patented Oct. 16,1923.

UNITED ...STATES osKAR HnIMsrnr, or vrENNa, AUSTRIA.

smnnnoscorrc Vniznrrncn ron'iiircnoscorns.

` Application f iled February 23, 1921. Serial No'.*l-47,097.,`

l (GRANTEDnnnnnrnnlrnovrsrous or THE Aer or Manon a,v i921, 211 s'in'ir.` L.,i313.`)

fo all w 7mm t may concern: i f `Be itknoWIr` that `I, OsKAnf yHniusrio'r, ,opt ician, acitizen of the German Republic, andresiding atwVienna, in the Republic of Austria, have invented certain new and use-` Y, iul Improvements in or. Relating to stereo-r scopic Eyepieces for Microscopes (for which I `have obtained patents inlGermany,-t1led July 29, V1919fjrranted Nov. 10, 1920, No.l

1ol 3320,25, and No. 339013, cred July ai, i920, f granted Mayr-10, 1921;.` in France, Jhled October 21, 1920, Igranted .I une 29, 1921,-No.

1. A526308; in Italy,:le'd November 3, 1920, No.

12S/54:9; vGrreat Britain, tiled July 29, 1920,'

15 ro. 14.9636, amino. `167130, vtied october er, "11929, and Austria,No. 86836, tiled January 19, 1920, granted October 6, 11921) 5 and I do lhereby decla-re the following tobe a `t'ull,

clear, and exact ydescription oi' the invention,

2Osuch as Will enable 'others skilled in the art i to which it appertains to make and use `the same, reference being had to the accompany# 30. is fused. i l

Such ystereo-Inicroscopes are provided :with an. additional.double/microscope yadapted for,A

= stereoscopic observation, which embodies one -o1= tivo objectivesy andtivo eye-piecesu. yBy means of this double microscope the, real 40, seen.

, The,y subject matter: of the present inven-Mv 31.-..tionwc'onsists in the conversionof such a fstereo-microscopev4 into a stereoscopic eye piecefor microscopes which can be employed with ,the usual stands; vlThe,opticalarrangement of suchan eye` ,Y p piece as id-iagrammatically illustrated inthe consists of an ad-rr '--ditionalydoublemic'roscope provided with:v .50`l Aonly oneyobjective llens 01, by means of which ',fobservation is made o fthejimage produced 4 ',-f in theplaneofthe/diaphragm o byfthepri-'f mary microscope objective o and by the posi- 11,' A"length of 01, asis clearly shovvnby the Acourse accompanying drawing,

tive auxiliary system a.

[,image` ofmthe object,projected by the pri-` \-mary.objective andproducedby a-pencil of ,f 4raysythe outerrays of which form a larger angle with the;y axisof the pencil of rays is* It has been found that vthespherical relief effect oi' a double microscope c`omprising a single objective, is the more striking, n

`the larger the exit pupils of the instrument.

This phenomenon` can be explained inthe following manner.- A stereoscopic effect can be obtained even with a `monocula'r ymicroscope, provided an objective `of large lens diameter, such, (for instanceas that listed by many large firms 'as objective No. 3)k be employed in combinationwith aI low-power eye-piece, usually listed as No. I or II. The

exit pupil'of the instrument their lbecomes ,I

yiris diaphragm-of the microscopebe contracted so as to reduce the exit pupils ofA the y `stereoscopic microscope.

The size ofthe exit pupils is, however, a -functioniof the magnification as theless ,the Ylatter,`the greater `Willi bethe former.

The stereoscopic relief, Whenf-incrle'ase'dfto the highest degree is, consequently, accompanied` by consideiable loss" ofmagnifying power, this: drawback, however, becoming .unimportant under the special'circumstances of the present arrangement. f

if ilarge increase of the exit pupils may beobtained in the :folloivingmanner ,The positive auxiliarysystem c is brought as close as possible to the primary microscope objective Vlens o, thus reducing the length of the'combination; This position of theauxil-` iary system is at thesame 'time adapted also to secure alarge visual field together with uniform illumination. `'Ihefocal length of the auxiliary system a and that of the microf scope objective lensV 01 must be so chosen that `the Width of the pencilr of rays proceeding from an `object .Y point situated uponu the optical axis falling on the'objective o?Y is larger than that leaving ther microscope obA jectiyeo; that is toLsa-y that the *strengthof` vthe auxiliary-system a is such thattherear focal ylength of: the combination'I of opand a taken togetherisless than the front` focal pencils of rays forming the image.

of the lines marked with arrow/heads which indicate the course of therays of light proceeding vfrom an object point up to theirY emergence from the eye-piece.l instead of the diaphragm Z), wherethe ,primaryv image is produced, there can bel employed what may be styled a eld lens, this being especially advantageous when the eyepiece is to be employed in combination with a low power objective for `the purpose of making microscopical preparations.

j As is the case in former stereoscopic microscopes, what is commonly termed the sharpness of the two divided images is impaired by the separation of the individiilal T is y defect is, however, materially reduced in consequence of the fact that the two partial pencils into which the lightis separated by ythe prisms pland p2 are of unlike diameter,

this being simply attained by giving an eccentric position to these prisms, so that the separating edge of the prism p1 does not lie on the optical axis of the lens 01, indicated by the broken line g 7L,- but is laterally displaced to a certainextent las shown by the drawings. The resultofl this arrangement is that the sharpness of the image which is formed by the pencils with a large cross section is perceptibly increased. The second image which is then of substantially lower luminosity and also` generally inferior, has for its sole function the production of apparent (superficial)inequality through itsparallactic difference, the transmission of details being performed entirely by the first image. y Y

The difference in the diameters of the individual object glasses VresultsI in causing the two shares or parts into whichvthe cone or pencil is separatedto take up vdifferent positions with'oneand the same eccentricity of the prism position. These differences can be compensatedfor by adjusting'the` casing c carrying theprisms in relation to the objective 01.' The slight displacement of the two divided images which occurs in this way as it takes place inthe sameV direction, does not affect'the stereoscopic effect at `all land affects the stereoscopic image as such only very slightly, more'especially as the displacements of the prisms are but slight in relation to the objective o1.

The constructional formsof stereoemicrovscopes without crossing the pencils producing the partial images are `all pseudoscopic.

.The transposition. of the images to yield stereoscopic relief can, however, vbe effected by known means, as for instance by the Nachet prism combination.` In the present constructional form of stereoscopic .microscope Ithere is adopted a new type of image transposition, whichV has the advantage of' enabling the instrument f to Ybe very com- .pac-tly built up; The `arrangement of the not hypothenuse two separating prisms is in this construetion such that their adjacent surfaces are i surfaces but surfaces bounding the right angles whilst the prisms are staggered or'displaced in relation to each other to the extent of their own height, so that the partial pencils or rays coming from each of the prisms p1, p2 can pass through Without obstruction by the other prism. r1`he division of the pencil of rays commences at the edge of the lower prism p1, and takes place along the plane 'common to the two surfaces turned towards each other. After transposition the two parts of the dividedy pencil of rays are taken up by the deflecting prisms p3 and pf which are rigidly connected to the tubes carrying the eye-pieces Z1 and Zzyand are simultaneously displaceable for adjustment to the interocular distance of the. observer.

1f for-the primarymicroscope objectivev o there be substituted a magnifying glass that can be slid upon .the tube carrying the auxiliary system a; the eye-pieceV will then become an orthoscopic magnifying glass with a stereoscopic effect and of a working distance dependent upon the focal length of the magnifying glass sliding upon it. rllhe same effect can also be obtainedif the auX- iliary lens system a be so varranged that it can be moved in opposition to `the object glass 01 of the double microscope, so as to vary the distance between them. The drawing shows such an arrangement wherein the tubem carrying the lens @slides on the inner tube n. y

Finally the stereoscopic-eyepiece' may if desired be connected with'the objective lens of a telescope. Through the parallactic differences of the image formed by the telescope objective there will also arise, as in the case of the microscope, a stereoscopic `effect which although less than with a double telescope is still distinctly observable. If the eye-piece be frequently used in the open air or out of doors as a magnifying glass, after the manner of the so called vivoscope, this simple transformation into a telescope which, by removal of the tube part carrying the lens and the substitution of another which, however, carries a tele?v scope with long focal distance, will certainly be welcome; On passing over from its working position as microscope eye-piece into its position of 'use as a magnifying glass, which is effected by displacement of the auxiliary system a, the auxiliary lens adopts a position in which the path of rays W hat I claim is: y 1. rlhe combination of a microscope having a primary objective, and an auxiliaryy system, a binocular eye-piece for the microscope having a single objective lens, and means whereby the auxiliary system may be brought close to the 'primary objective, the combined focal length of the latter and the auxiliary system being less than the focal length of the objective lens. j f

2. The combination With a microscope having a primary objective, and an auxiliary system, of a binocular eye-piece for the microscope having a single objective lens, and means for adjusting the auxiliary system relatively to the primary objective whereby the combined rear focal length of the primary objective and the auxiliary systcm is less than the front focal length of` the single objective lens.

3. The combination with a microscope having an image producing primary objective, and an auxiliary system, of a binocular eye-piece for the microscope having a single objective lens, and prisms mounted in the eye piece for effecting the separation of the pencil of rays, said prisms being arranged eccentrically in relation to the objective lens of the binocular eye-piece.. y 4. The combination with a microscope having an image producing primary objective, and an auxiliary system, of a binocular eye-piece for the microscope having a single objective lens, means for adjusting the auxiliary system relatively to the primary objective, prisms mounted in the eye piece for effecting the separation of thepencil rays and having their separating edges ar'-, ranged eccentrically to the vobjective lens,

eye-piece for the microscope having a single objective lens, means for adjusting the auxiliary system relatively to the primary objective, a pair of right angled prisms mounted in the eye-piece for the transposi-` tion of the image formed by the separation ot the pencil rays, said prisms having two surfaces in approximately the same plane and in staggered relation to` each other.l

'6. The combination of a microscope hav ing a primary objective, and an auxiliary system, a binocular eye-piece for the microscope having a single objective lens, a tube carrying the auxiliary system telescopically connected with the microscope whereby said auxiliary system may be adjusted relatively` to the primary objective, and prisms mounted in the eye pieces for effecting t-he separation of the pencil rays and having surfaces in approximate-ly the same plane, and in staggered relation to each other to the extent of their height. i v

In testimony that I claim the foregoing as my invention, I have signed my name.

osKAR HEIMsTDT. 

